Process for preparing bicyclo[2.2.1] heptane derivatives

ABSTRACT

The invention relates to economical and efficient methods for producing 2-methylene-3-methylbicyclo[2,2,1]heptane, 2,3-dimethylbicyclo[2.2.1]hept-2-ene and the like that are useful for materials of producing base oil of traction drive fluid for traction drive lubricating oil. The methods comprise reacting one or more C 3-4  acyclic olefins with cyclopentadiene and isomerizing the resulting bicyclo[2.2.1]heptene derivatives in the presence of an isomerization catalyst to give one or more bicyclo[2.2.1]heptane derivatives.

TECHNICAL FIELD

[0001] The present invention relates to novel methods for producingbicyclo[2.2.1]heptane derivatives. More precisely, the invention relatesto economical and efficient methods for producing2-methylene-3-methylbicyclo[2.2.1]heptane,2,3-dimethylbicyclo[2.2.1]hept-2-ene, 2-ethylidenebicyclo[2.2.1]heptaneand 2-ethylbicyclo[2.2.1]-hept-2-ene that are useful for materials ofproducing a base oil of traction drive fluid used for a lubricating oilfor driving a fraction drive apparatus.

BACKGROUND ART

[0002] Traction drive fluid that is used for traction drive lubricatingoil for driving a traction drive apparatus for stepless regulators inautomobiles and industrial machines is required to have specificproperties of high traction coefficient and low pour point. To meet therequirement, cyclic compound derivatives are used in base oil oftraction drive fluid. For example, dimers of bicyclo[2.2.1]heptanederivatives have been proposed (Japanese Patent No. 2,060,214).

[0003] Therefore, bicyclo[2.2.1]heptane derivatives, especially2-methylene-3-methylbicyclo[2.2.1]heptane,2,3-dimethylbicyclo[2.2.1]hept-2-ene, 2-ethylidenebicyclo[2.2.1]heptaneand 2-ethylbicyclo[2.2.1]-hept-2-ene are important compounds asmaterials for producing base oil of traction drive fluid.

[0004] Heretofore, the compounds of the type are obtained, for example,by reacting crotonaldehyde with dicyclopentadiene through Diels-Alderreaction, then hydrogenating the reaction product and dehydrating it.The process of producing bicyclo[2.2.1] compounds requires three stepsof Diels-Alder reaction, hydrogenation and dehydration. Another problemwith the process is that the reactant crotonaldehyde is relativelyexpensive and therefore the production costs are high.

[0005] Accordingly, it is desired to develop more economical andefficient novel methods of producing bicyclo[2.2.1]heptane derivatives.

[0006] The present invention has been made in consideration of theabove-mentioned point, and its object is to provide economical andefficient methods for producing bicyclo[2.2.1]heptane derivatives suchas 2-methylene-3 methylbicyclo [2.2.1] heptane, 2,3- dimethylbicyclo[2.2.1] hept-2-ene,   2-

[0007] ethylidenebicyclo[2.2.1]heptane and2-ethylbicyclo[2.2.1]-hept-2-ene.

DISCLOSURE OF THE INVENTION

[0008] We, the present inventors have assiduously studied to attain theabove-mentioned object and, as a result, have found that the object canbe effectively attained by starting from relatively inexpensive andeasily available compounds and selecting the reaction condition of thecompounds. On the basis of this finding, we have completed the presentinvention.

[0009] Accordingly, the invention is summarized as follows:

[0010] <1> A method for producing bicyclo[2.2.1]heptane derivatives,which comprises reacting one or more C₃₋₄ acyclic olefins withcyclopentadiene to give bicyclo[2.2.1]heptene derivatives of thefollowing general formula (I):

[0011] wherein R¹ and R² each represent a hydrogen atom, a methyl groupor an ethyl group, and the sum of the carbon atoms in R¹ and R² is 1 or2,

[0012] followed by isomerizing them in the presence of an isomerizationcatalyst to give one or more bicyclo[2.2.1]heptane derivatives of thefollowing general formula (II):

[0013] wherein R³ and R⁴ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R³ and R⁴ is 0 or 1, thefollowing general formula (III):

[0014] wherein R⁵ and R⁶ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and thefollowing general formula (IV):

[0015] wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl groupor an ethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or2.

[0016] <2> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <1>, wherein the acyclic olefin is 2-butene, thebicyclo[2.2.1]heptene derivative of general formula (I) is5,6-dimethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptanederivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2,3-dimethylbicyclo[2.2.1]hept-2-ene.

[0017] <3> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <1>, wherein the acyclic olefin is 1-butene, thebicyclo[2.2.1]heptene derivative of formula (I) is5-ethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptane derivative offormula (II) or (III) is 2-ethylidenebicyclo[2.2.1]heptane, and thebicyclo[2.2.1]heptane derivative of formula (IV) is2-ethylbicyclo[2.2.1]hept-2-ene.

[0018] <4> A method for producing bicyclo[2.2.1]heptane derivatives,which comprises reacting one or more C₃₋₄ acyclic olefins withcyclopentadiene in the presence of an isomerization catalyst forsimultaneous isomerization to give one or more bicyclo[2.2.1] heptanederivatives of the following general formula (II):

[0019] wherein R³ and R⁴ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R³ and R⁴ is 0 or 1, thefollowing general formula (III):

[0020] wherein R⁵ and R⁶ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and thefollowing general formula (IV):

[0021] wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl groupor an ethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or2.

[0022] <5> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <4>, wherein the acyclic olefin is 2-butene, thebicyclo[2.2.1]heptane derivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of general formula (IV) is2,3-dimethylbicyclo[2.2.1]hept-2-ene.

[0023] <6> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <4>, wherein the acyclic olefin is 1-butene, thebicyclo[2.2.1]heptane derivative of formula (II) or (III) is2-ethylidenebicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2-ethylbicyclo[2.2.1]hept-2-ene.

[0024] <7> A method for producing bicyclo[2.2.1]heptane derivatives,which comprises isomerizing bicyclo[2.2.1]heptene derivatives of thefollowing general formula (I):

[0025] wherein R¹ and R² each represent a hydrogen atom, a methyl groupor an ethyl group, and the sum of the carbon atoms in R¹ and R² is 1 or2,

[0026] in the presence of an isomerization catalyst to give one or morebicyclo[2.2.1]heptane derivatives of the following general formula (II):

[0027] wherein R³ and R⁴ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R³ and R⁴ is 0 or 1, thefollowing general formula (III):

[0028] wherein R⁵ and R⁶ each represent a hydrogen atom or a methylgroup, and the sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and thefollowing general formula (IV):

[0029] wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl groupor an ethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or2.

[0030] <8> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <7>, wherein the bicyclo[2.2.1]heptene derivative of formula (I)is 5,6-dimethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptanederivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2,3-dimethylbicyclo[2.2.1]hept-2-ene.

[0031] <9> The method for producing bicyclo[2.2.1]heptane derivatives ofabove <7>, wherein the bicyclo[2.2.1]heptene derivative of formula (I)is 5-ethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptane derivativeof formula (II) or (III) is 2-ethylidenebicyclo[2.2.1]heptane, and thebicyclo[2.2.1]heptane derivative of formula (IV) is2-ethylbicyclo[2.2.1]hept-2-ene.

[0032] <10> The method for producing bicyclo[2.2.1]heptane derivativesof any of above <1> to <9>, wherein the isomerization catalyst is asolid acid catalyst.

[0033] <11> The method for producing bicyclo[2.2.1]heptane derivativesof any of above <1> to <6> and <10>, wherein dicyclopentadiene is usedin place of cyclopentadiene and, while pyrolyzed into cyclopentadiene,it is reacted with one or more C₃₋₄ acyclic olefins.

BEST MODES OF CARRYING OUT THE INVENTION

[0034] Modes of carrying out the invention are described below.

[0035] According to the methods of the invention, C₃₋₄ acyclic olefinsare reacted with cyclopentadiene to give the intendedbicyclo[2.2.1]heptane derivatives. The C₃₋₄ acyclic olefins include, forexample, 1-butene, 2-butene and propylene. Of those, 2-butene and1-butene are preferred for the starting compounds in the invention.

[0036] One embodiment of the invention in which the acyclic olefin is2-butene are described in detail.

[0037] In this embodiment, the starting compounds, 2-butene andcyclopentadiene are reacted with each other, and the resulting5,6-dimethylbicyclo[2.2.1]hept-2-ene is isomerized in the presence of anisomerization catalyst to give 2-methylene-3-methylbicyclo[2.2.1]heptaneand/or 2,3-dimethylbicyclo[2.2.1]hept-2-ene. The intermediate5,6-dimethylbicyclo[2.2.1]hept-2-ene in this method of the invention isrepresented by the following chemical formula (V), and the finalproducts 2-methylene-3-methylbicyclo[2.2.1]heptane and2,3-dimethylbicyclo[2.2.1]hept-2-ene are by the following chemicalformulae (VI) and (VII), respectively:

[0038] According to the method, the bicyclo[2.2.1]heptane derivativescan be produced in at least 2 steps starting from inexpensive 2-buteneand cyclopentadiene. In addition, they can be produced only in one step,as described hereinunder.

[0039] In the invention, the starting compounds, 2-butene andcyclopentadiene are reacted with each other. This is Diels-Alderreaction.

[0040] One starting compound, 2-butene may be trans-2-butene orcis-2-butene alone or may be their mixture. These are inexpensive andeasily available.

[0041] The other stating compound, cyclopentadiene may becyclopentadiene itself, or may also be derived from dicyclopentadiene insitu. When heated, dicyclopentadiene is readily pyrolyzed to givecyclopentadiene, and the resulting cyclopentadiene is substantiallyreacted with 2-butene. In other words, dicyclopentadiene is, whilepyrolyzed to give cyclopentadiene, reacted with 2-butene throughDiels-Alder reaction.

[0042] The blend ratio of the starting compounds, 2-butene andcyclopentadiene is not specifically defined. Preferably, however,2-butene is excessive over its theoretical amount, or that is, the ratioof 2-butene/cyclopentadiene (by mol) is at least 1 or more. If the blendratio of the starting compounds is smaller than 1, the reaction mixturemay contain a large quantity of heavy compounds in addition to theintended products. More preferably, the blend ratio of the startingcompounds falls between 2 and 20, even more preferably between 4 and 15.

[0043] In the invention, the starting compounds mentioned above arereacted with each other through Diels-Alder reaction. The reaction isgenerally effected at about 20 to 400° C., but preferably at 100 to 350°C. However, when dicyclopentadiene is used in place of cyclopentadieneand it is pyrolyzed into cyclopentadiene, the reaction is preferablyeffected at 150 to 350° C. This is for promoting the pyrolysis ofdicyclopentadiene.

[0044] The Diels-Alder reaction pressure is not also specificallydefined, and the reaction may be effected under any pressure. Ingeneral, the starting compounds are reacted under no specific pressure,but the vapor pressure of 2-butene increases the reaction pressure, andthe pressure varies depending on the reaction temperature.

[0045] The Diels-Alder reaction gives the intermediate of the invention,5,6-dimethylbicyclo[2.2.1]hept-2-ene of formula (V).

[0046] In the invention, this 5,6-dimethylbicyclo[2.2.1]hept-2-ene isisomerized in the presence of an isomerization catalyst.

[0047] Preferably, the isomerization catalyst is an acidic solidcatalyst generally referred to as a solid acid catalyst. Concretely, forexample, it includes metal oxides such as alumina, silica, titania,zirconia, chromia, zinc oxide, silica-alumina, silica-magnesia,alumina-boria, silica-boria, silica-zirconia; metal phosphates such ascalcium phosphate, zirconium phosphate, calcium hydroxyapatite; metalsulfates such as magnesium sulfate, calcium sulfate, aluminium sulfate;phyllosilicates such as bentonite, montmorillonite, kaolin; clays suchas activated clay, acid clay; solid acids prepared by infiltrating solidphosphoric acid or sulfuric acid into silica or alumina; and otherion-exchange resins and zeolite. Of those solid acid catalysts,silica-alumina, alumina-boria and zeolite have a high acid strength;titania and montmorillonite have a medium acid strength; and alumina andsilica have a low acid strength.

[0048] The acid strength of catalyst is generally indicated by theacidity function thereof.

[0049] Of the solid acid catalysts mentioned above, preferred are thosehaving a middle to high acid strength, as their ability to realize highconversion and high selectivity is good.

[0050] Correlated with the charge of the starting compounds into thereaction system, the catalyst is generally so controlled that its weighthourly space velocity, WHSV falls between 0.01 and 20 h⁻¹, preferablybetween 0.1 and 10 h⁻¹.

[0051] Like the Diels-Alder reaction, the isomerization may be effectedin the absence or presence of a solvent such as an organic solvent.

[0052] The isomerization temperature preferably falls between about 20and 400° C., more preferably between about 50 and 250° C. If thereaction temperature is lower than about 20° C., the isomerization willbe delayed and the method will be impracticable; but if higher than 400°C., the products will be pyrolyzed. The preferred reaction temperaturerange varies, depending on the acid strength of the isomerizationcatalyst used. For example, when the acid strength of the isomerizationcatalyst used is high, the reaction temperature may fall between 20° C.and 150° C.; when it is medium, the temperature may fall between 150° C.and 250° C.; and when it is low, the temperature may fall between 250°C. and 400° C.

[0053] On the other hand, the isomerization pressure is not specificallydefined, and may be effected under any pressure. In general, theisomerization is effected under no specific pressure.

[0054] In the manner as above, 2-methylene-3-methylbicyclo[2.2.1]heptaneand/or 2,3-dimethylbicyclo[2.2.1]hept-2-ene of formulae (VI) and (VII)are obtained.

[0055] As mentioned above, the method of the invention comprises twosteps of Diels-Alder reaction and isomerization to give thebicyclo[2.2.1]heptane derivatives of formulae (VI) and/or (VII). Apartfrom it, the bicyclo[2.2.1]heptane derivatives can also be produced inone step.

[0056] The method of the invention to give the bicyclo[2.2.1]heptanederivatives in one step comprises reacting 2-butene with cyclopentadienein the presence of an isomerization catalyst for simultaneousisomerization to give 2-methylene-3-methylbicyclo[2.2.1]heptane and/or2,3-dimethylbicyclo[2.2.1]hept-2-ene.

[0057] In this method, the two-step reactions go on efficiently andalmost simultaneously.

[0058] The one-step method does not substantially differ from thetwo-step method except for the point that the isomerization catalyst isin the initial reaction system. Therefore, the details of theisomerization catalyst to be used and those of the starting compounds tobe reacted and their blend ratio in the one-step method may besubstantially the same as those in the above-mentioned two-step method.In addition, the two methods do not also substantially differ in pointof the other reaction conditions such as reaction temperature andreaction pressure. Accordingly, the reaction temperature in the one-stepmethod may fall between about 20 and 400° C., preferably between 100 and350° C. More preferably, it falls between 150 and 350° C. when thereaction starts from dicyclopentadiene. Regarding the reaction pressure,the system does not require any specific pressure, and its pressure maybe the vapor pressure at the reaction temperature.

[0059] According to the one-step method,2-methylene-3-methylbicyclo[2.2.1]heptane and/or2,3-dimethylbicyclo[2.2.1]hept-2-ene are also produced efficiently.

[0060] The above-mentioned methods apply to C₃₋₄ acyclic olefins except2-butene to give the corresponding bicyclo[2.2.1]heptanes. For example,when 1-butene is used in place of 2-butene, it gives an intermediate,5-ethylbicyclo[2.2.1]hept-2-ene, and then2-ethylidenebicyclo[2.2.1]heptane and/or 2-ethylbicyclo[2.2.1]hept-2-enethrough isomerization. When propylene is used in place of 2-butene, itgives an intermediate, 5-methylbicyclo[2.2.1]hept-2-ene, and then2-methylidenebicyclo[2.2.1]heptane and/or2-methylbicyclo[2.2.1]hept-2-ene through isomerization.

[0061] When a mixture of two or more C₃₋₄ acyclic olefins is used, itgives a mixture of intermediates, [2.2.1]heptene derivatives, and then amixture of their isomers, [2.2.1]heptane derivatives throughisomerization.

[0062] Therefore, for example, an acyclic olefin mixture of 2-butene and1-butene gives a mixture of 2-methylene-3- methylbicyclo [2.2.1]heptane, 2,3- dimethylbicyclo [2.2.1] hept-2-ene,   2- ethylidenebicyclo[2.2.1] heptane and   2- ethylbicyclo [2.2.1] hept-2-ene.

[0063] The products of the above-mentioned methods, 2methylene-3-methylbicyclo [2.2.1] heptane, 2,3- dimethylbicyclo [2.2.1]hept-2-ene,   2- ethylidenebicyclo [2.2.1] heptane and   2-

[0064] ethylbicyclo[2.2.1]hept-2-ene are useful as synthetic materialsfor producing base oil to be in traction drive fluid.

[0065] The invention is described more concretely with reference to thefollowing Examples, which, however, are not intended to restrict thescope of the invention.

EXAMPLE 1

[0066] (Two-Step Method)

[0067] 324 g (5.78 mols) of mixed 2-butene (trans/cis=62/38), and 66.8 g(0.51 mols) of dicyclopentadiene were put into a one-liter stainlessautoclave, and reacted at 240° C. for 3 hours. After cooled, thereaction mixture was distilled to collect 49 g of 140° C. fraction. Thefraction was analyzed through mass spectrometry and nucleic magneticresonance spectrometry, and the result confirmed that the fraction is5,6-dimethylbicyclo[2.2.1]hept-2-ene.

[0068] A flow-type normal pressure reaction tube of quartz glass havingan outer diameter of 20 mm and a length of 500 mm was filled with 25 gof alumina-boria (ShokubaiKasei Kogyo's C-15), and the fraction wasintroduced into it and isomerized at 155° C. and at a weight hourlyspace velocity (WHSV) of 1.0 hr⁻¹. This gave 48 g of an isomerizedproduct of 5,6-dimethylbicyclo[2.2.1]hept-2—ene, containing 62%2,3-dimethylbicyclo[2.2.1]hept-2-ene and 28%2-methylene-3-methylbicyclo[2.2.1]heptane.

EXAMPLE 2

[0069] (Two-Step Method)

[0070] The same process as in Example 1 was repeated except for thefollowing points. Trans-2-butene was used in place of the mixed2-butene, a silica-alumina catalyst (Nikki Chemical's N-632L) was inplace of the alumina-boria catalyst, and the isomerization was effectedat 110° C. but not at 155° C. This gave 48 g of an isomerized product of5,6-dimethylbicyclo[2.2.1]hept-2-ene, containing 52%2,3-dimethylbicyclo[2.2.1]hept-2-ene and 20%2-methylene-3-methylbicyclo[2.2.1]heptane.

EXAMPLE 3

[0071] (One-Step Method)

[0072] 45 g (0.8 mols) of mixed 2-butene (trans/cis=62/38), 5.6 g (0.042mols) of dicyclopentadiene, and 10 g of a catalyst, γ-alumina (NikkiChemical's N613N) were put into a 200-cc stainless autoclave, andreacted at 240° C. for 5 hours. After cooled, this was analyzed throughgas chromatography. The result confirmed that the reaction productcontains 9% 2,3-dimethylbicyclo[2.2.1]hept-2-ene and 4%2-methylene-3-methylbicyclo[2.2.1]heptane, in addition to5,6-dimethylbicyclo[2.2.1]hept-2-ene.

EXAMPLE 4

[0073] (One-Step Method)

[0074] The same process as in Example 3 was repeated except that 15 g ofsilica-containing γ-alumina (Shokubai Kasei Kogyo's DHC-1) but not 10 gof y-alumina was used as the catalyst. This gave 6 g of an isomerizedproduct of 5,6-dimethylbicyclo[2.2.1]hept-2-ene, containing 64%2,3-dimethylbicyclo[2.2.1]hept-2-ene and 26%2-methylene-3-methylbicyclo[2.2.1]heptane.

EXAMPLE 5

[0075] (Two-Step Method)

[0076] The same process as in Example 1 was repeated except that1-butene was used in place of the mixed 2-butene. This gave 93 g of anisomerized product of 5-ethylbicyclo[2.2.1]hept-2-ene, containing 67%2-ethylbicyclo[2.2.1]hept-2-ene and 29%2-ethylidenebicyclo[2.2.1]heptane.

EXAMPLE 6

[0077] (Two-Step Method)

[0078] 80 g (1.43 mols) of mixed n-butene (35 wt. % 1-butene, 40 wt. %trans-2-butene, 25 wt. % cis-2-butene), and 13.2 g (0.10 mols) ofdicyclopentadiene were put into a 200-cc stainless autoclave, andreacted at 240° C. for 3 hours. After cooled, the reaction mixture wasdistilled to collect 18 g of 140° C. fraction comprised of 75%5-ethylbicyclo[2.2.1]hept-2-ene and 25%5,6-dimethylbicyclo[2.2.1]hept-2-ene.

[0079] A flow-type normal pressure reaction tube of quartz glass havingan outer diameter of 20 mm and a length of 500 mm was filled with 25 gof alumina-boria (ShokubaiKasei Kogyo's C-15), and the fraction wasintroduced into it and isomerized at 155° C. and at a weight hourlyspace velocity (WHSV) of 1.0 hr⁻¹. This gave 17 g of an isomerizedproduct of 5,6-dimethylbicyclo[2.2.1]hept-2-ene and5-ethylbicyclo[2.2.1]hept-2-ene, containing 15%2,3-dimethylbicyclo[2.2.1]hept-2-ene, 6%2-methylene-3-methylbicyclo[2.2.1]heptane, 49%2-ethylbicyclo[2.2.2]hept-2-ene and 21%2-ethylidenebicyclo[2.2.1]heptane.

COMPARATIVE EXAMPLE 1

[0080] The same process as in Example 2 was repeated except thatisomerizing the distilled fraction was tried with ceramic balls at 250°C., not with the silica-alumina catalyst (Nikki Chemical's N-632L) at110° C., but in vain. In this, the starting compound5,6-dimethylbicyclo[2.2.1]hept-2-ene was not isomerized and was directlycollected still as it was after the process.

INDUSTRIAL APPLICABILITY

[0081] Starting from inexpensive acyclic olefins such as 2-butene and1-butene, the methods of the invention give the intendedbicyclo[2.2.1]heptane derivatives such as 2 methylene-3-methylbicyclo[2.2.1] heptane, 2,3- dimethylbicyclo [2.2.1] hept-2-ene,   2-

[0082] ethylidenebicyclo[2.2.1]heptane and2-ethylbicyclo[2.2.1]-hept-2-ene only in one step or two steps, and themethods are economical and efficient.

1. A method for producing bicyclo[2.2.1]heptane derivatives, whichcomprises reacting one or more C₃₋₄ acyclic olefins with cyclopentadieneto give bicyclo[2.2.1]heptene derivatives of the following generalformula (I):

wherein R¹ and R² each represent a hydrogen atom, a methyl group or anethyl group, and the sum of the carbon atoms in R¹ and R² is 1 or 2,followed by isomerizing them in the presence of an isomerizationcatalyst to give one or-more bicyclo[2.2.1]heptane derivatives of thefollowing general formula (ii):

wherein R³ and R⁴ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R³ and R⁴ is 0 or 1, the followinggeneral formula (III):

wherein R⁵ and R⁶ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and the followinggeneral formula (IV):

wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl group or anethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or
 2. 2.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 1, wherein the acyclic olefin is 2-butene, thebicyclo[2.2.1]heptene derivative of formula (I) is5,6-dimethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptanederivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2,3-dimethylbicyclo[2.2.1]hept-2-ene. 3.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 1, wherein the acyclic olefin is 1-butene, thebicyclo[2.2.1]heptene derivative of formula (I) is5-ethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptane derivative offormula (II) or (III) is 2-ethylidenebicyclo[2.2.1]heptane, and thebicyclo[2.2.1]heptane derivative of formula (IV) is2-ethylbicyclo[2.2.1]hept-2-ene.
 4. A method for producingbicyclo[2.2.1]heptane derivatives, which comprises reacting one or moreC314 acyclic olefins with cyclopentadiene in the presence of anisomerization catalyst for simultaneous isomerization to give one ormore bicyclo[2.2.1]heptane derivatives of the following general formula(II):

wherein R³ and R⁴ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R³ and R⁴ is 0 or 1, the followinggeneral formula (III):

wherein R⁵ and R⁶ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and the followinggeneral formula (IV):

wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl group or anethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or
 2. 5.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 4, wherein the acyclic olefin is 2-butene, thebicyclo[2.2.1]heptane derivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2,3-dimethylbicyclo[2.2.1]hept-2-ene. 6.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 4, wherein the acyclic olefin is 1-butene, thebicyclo[2.2.1]heptane derivative of formula (II) or (III) is2-ethylidenebicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2-ethylbicyclo[2.2.1]hept-2-ene.
 7. Amethod for producing bicyclo[2.2.1]heptane derivatives, which comprisesisomerizing bicyclo[2.2.1]heptene derivatives of the following generalformula (I):

wherein R¹ and R² each represent a hydrogen atom, a methyl group or anethyl group, and the sum of the carbon atoms in R¹ and R² is 1 or 2, inthe presence of an isomerization catalyst to give one or morebicyclo[2.2.1]heptane derivatives of the following general formula (II):

wherein R³ and R⁴ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R³ and R⁴ is 0 or 1, the followinggeneral formula (III):

wherein R⁵ and R⁶ each represent a hydrogen atom or a methyl group, andthe sum of the carbon atoms in R⁵ and R⁶ is 0 or 1, and the followinggeneral formula (IV):

wherein R⁷ and R⁸ each represent a hydrogen atom, a methyl group or anethyl group, and the sum of the carbon atoms in R⁷ and R⁸ is 1 or
 2. 8.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 7, wherein the bicyclo[2.2.1]heptene derivative of formula (I) is5,6-dimethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptanederivative of formula (II) or (III) is2-methylene-3-methylbicyclo[2.2.1]heptane, and the bicyclo[2.2.1]heptanederivative of formula (IV) is 2,3-dimethylbicyclo[2.2.1]hept-2-ene. 9.The method for producing bicyclo[2.2.1]heptane derivatives as claimed inclaim 7, wherein the bicyclo[2.2.1]heptene derivative of formula (I) is5-ethylbicyclo[2.2.1]hept-2-ene, the bicyclo[2.2.1]heptane derivative offormula (II) or (III) is 2-ethylidenebicyclo[2.2.1]heptane, and thebicyclo[2.2.1]heptane derivative of formula (IV) is2-ethylbicyclo[2.2.1]hept-2-ene.
 10. The method for producingbicyclo[2.2.1]heptane derivatives as claimed in any of claims 1 to 9,wherein the isomerization catalyst is a solid acid catalyst.
 11. Themethod for producing bicyclo[2.2.1]heptane derivatives as claimed in anyof claims 1 to 6 and 10, wherein dicyclopentadiene is used in place ofcyclopentadiene and, while pyrolyzed into cyclopentadiene, it is reactedwith one or more C₃₋₄ acyclic olefins.